

namespace Petaframe.Validation.TestHelper {
	using System;
	using System.Linq.Expressions;
	using Internal;
	using System.Linq;
	using Validators;

	public static class ValidationTestExtension {
		public static void ShouldHaveValidationErrorFor<T, TValue>(this IValidator<T> validator,
		                                                           Expression<Func<T, TValue>> expression, TValue value) where T : class, new() {
			new ValidatorTester<T, TValue>(expression, validator, value).ValidateError(new T());
		}

		public static void ShouldHaveValidationErrorFor<T, TValue>(this IValidator<T> validator, Expression<Func<T, TValue>> expression, T objectToTest) where T : class {
			var value = expression.Compile()(objectToTest);
			new ValidatorTester<T, TValue>(expression, validator, value).ValidateError(objectToTest);
		}

		public static void ShouldNotHaveValidationErrorFor<T, TValue>(this IValidator<T> validator,
		                                                              Expression<Func<T, TValue>> expression, TValue value) where T : class, new() {
			new ValidatorTester<T, TValue>(expression, validator, value).ValidateNoError(new T());
		}

		public static void ShouldNotHaveValidationErrorFor<T, TValue>(this IValidator<T> validator, Expression<Func<T, TValue>> expression, T objectToTest) where T : class {
			var value = expression.Compile()(objectToTest);
			new ValidatorTester<T, TValue>(expression, validator, value).ValidateNoError(objectToTest);
		}

		public static void ShouldHaveChildValidator<T, TProperty>(this IValidator<T> validator, Expression<Func<T, TProperty>> expression, Type childValidatorType) {
			var descriptor = validator.CreateDescriptor();
			var matchingValidators = descriptor.GetValidatorsForMember(expression.GetMember().Name);

			var childValidators = matchingValidators.OfType<ChildValidatorAdaptor>().Select(x => x.Validator);
			childValidators = childValidators.Concat(matchingValidators.OfType<ChildCollectionValidatorAdaptor>().Select(x => x.Validator));

			if(! childValidators.Any(x => x.GetType() == childValidatorType)) {
				throw new ValidationTestException(string.Format("Expected property '{0}' to have a child validator of type '{1}.'", expression.GetMember().Name, childValidatorType.Name));
			}
		}

	}
}